1. Field of the Invention
This invention relates, in general, to workpiece holders for supporting workpieces in manufacturing operations.
2. State of the Art
Workpiece holders are employed in manufacturing operations to hold workpieces during manufacturing operations, such as, machining, welding or other forming operations, as well as to transport such workpieces between work stations. In automotive operations, workpiece holders are typically employed to handle vehicle body panels and subassemblies. These panels typically have lengths and widths of two or more feet and are frequently of irregular shape or formed with irregularly-shaped openings so that in order to stably and firmly support the panel, it is necessary that the work holders grip the panel at several locations along its peripheral edge or the edges of major openings in the panel.
Workpiece holders for such applications generally include a variety of grippers, clamps or vacuum cups which are mounted on support frames or support members. Despite the large variety of different types of workpiece holders, it is still desirable to provide a workpiece holder which has a low cost and an accurate operation. It would also be desirable to provide a workpiece holder which is capable of being mounted in a variety of positions via a number of different workpiece mounting members for use in a large number of different applications. It would also be desirable to provide a workpiece holder which is quick in operation and is capable of generating a high clamping or gripping force.